ACPAtmospheric Chemistry and PhysicsACPAtmos. Chem. Phys.1680-7324Copernicus GmbHGöttingen, Germany10.5194/acp-8-7055-2008Technical Note: The CCCma third generation AGCM and its extension into the middle atmosphereScinoccaJ. F.1McFarlaneN. A.1LazareM.1LiJ.1PlummerD.11Canadian Centre for Climate Modelling and Analysis, Environment Canada, Victoria, B. C., Canada0612200882370557074This work is licensed under a Creative Commons Attribution 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/This article is available from http://www.atmos-chem-phys.net/8/7055/2008/acp-8-7055-2008.htmlThe full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/7055/2008/acp-8-7055-2008.pdf

The Canadian Centre for Climate Modelling and Analysis third
generation atmospheric general circulation model (AGCM3) is
described. The discussion summarizes the details of the complete
physics package emphasizing the changes made relative to the second
generation version of the model. AGCM3 is the underlying model for
applications which include the IPCC fourth assessment, coupled
atmosphere-ocean seasonal forecasting, the first generation of the
CCCma earth system model (CanESM1), and middle-atmosphere
chemistry-climate modelling (CCM). Here we shall focus on issues
related to an upwardly extended version of AGCM3, the Canadian
Middle-Atmosphere Model (CMAM). The CCM version of CMAM
participated in the 2006 WMO/UNEP Scientific Assessment of Ozone
Depletion and issues concerning its climate such as the impact of
gravity-wave drag, the modelling of a spontaneous QBO, and the
seasonality of the breakdown of the Southern Hemisphere polar vortex
are discussed here.